[pdal] Migration to pdal.org

[Howard Butler]

All,

With the recent turmoil about the future of .io domains, which subsequently settled down for now, Hobu investigated and acquired the pdal.org domain, which hadn't previously been for sale when PDAL was founded. It is now a simple redirect to pdal.io, but over the next month or so, we will undertake a migration to pdal.org as the canonical domain for PDAL. Afterward, the .io domain will continue to permanently redirect to .org, but public URLs will slowly start migrating over to .org as we update them.

As with any migrations, there may be a few hiccups.

Howard